feat: allow to nest domains

README.md

@@ -11,7 +11,7 @@ Intercepts stdout/ stderr.
 
 ## Implementation
 
-This module uses [`domain`](https://nodejs.org/api/domain.html) to capture asyncrhonous function output.
+This module uses [`domain`](https://nodejs.org/api/domain.html) to capture asynchronous function output.
 
 Read [Capturing stdout/ stderr in Node.js using Domain module](https://medium.com/@gajus/capturing-stdout-stderr-in-node-js-using-domain-module-3c86f5b1536d).
 

src/factories/createOutputInterceptor.js

@@ -49,9 +49,7 @@ export default (userConfiguration?: OutputInterceptorUserConfigurationType): Out
   }
 
   const interceptor = async (routine) => {
-    if (process.domain) {
-      throw new Error('Cannot intercept output within an exiting domain context.');
-    }
+    const parentDomain: any = process.domain;
 
     const domain: any = createDomain();
 
@@ -81,6 +79,10 @@ export default (userConfiguration?: OutputInterceptorUserConfigurationType): Out
 
     interceptor.output = output;
 
+    if (parentDomain && parentDomain.outputInterceptor) {
+      parentDomain.outputInterceptor.output += output;
+    }
+
     if (routineError) {
       throw routineError;
     }

test/output-interceptor/factories/createOutputInterceptor.js

@@ -167,20 +167,27 @@ test('works as expected when multiple interceptors are constructed simultaneousl
   t.is(intercept.output, 'foo\n');
 });
 
-test('throws an error if an attempt is made to use output-interceptor within an existing domain', async (t) => {
+test('captures nested output-interceptor output', async (t) => {
   const intercept1 = createOutputInterceptor();
   const intercept2 = createOutputInterceptor();
 
-  const error = await t.throwsAsync(intercept1(async () => {
+  let output0;
+
+  await intercept1(async () => {
     console.log('foo');
 
     // eslint-disable-next-line require-await
     await intercept2(async () => {
       console.log('bar');
     });
 
+    output0 = intercept2.output;
+
     console.log('baz');
-  }));
+  });
+
+  const output1 = intercept1.output;
 
-  t.is(error.message, 'Cannot intercept output within an exiting domain context.');
+  t.is(output0, 'bar\n');
+  t.is(output1, 'foo\nbar\nbaz\n');
 });